Field of the Invention
The present invention relates to a technique of calculating a motion vector between a plurality of frame images. Specifically, the present invention relates to an image processing apparatus capable of improving accuracy in the calculation of the motion vector without increasing a processing load.
Description of the Related Art
There has been known a technique of selecting one image from a plurality of (n+1) frame images of a video image as a reference image and basing this reference image to calculate respective motion vectors for the other n frame images (comparative images).
Generally in the calculation of the motion vector, a feature point such as a corner of an object is extracted from the reference image and a point corresponding to the extracted feature point is obtained from each of the other n object images. For a technique of calculating motion vector at high speed, there has been known a technique of calculating a feature amount for every x pixels not in the reference image but in a blurred reference image (in a changed resolution) (refer to Japanese Patent Publication No. 3935500 specification, for example). As a similar technique, it has been known to be able to realize a high-speed feature point extraction by extracting the feature point in a reduced image which is obtained by the reduction of the reference image size.